From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
michael.neuling@au1.ibm.com, stewart@linux.vnet.ibm.com,
apopple@au1.ibm.com, hbabu@us.ibm.com, oohall@gmail.com,
bsingharora@gmail.com, linuxppc-dev@ozlabs.org,
linux-kernel@vger.kernel.org, aneesh.kumar@linux.vnet.ibm.com
Subject: Re: [PATCH v4 05/11] VAS: Define helpers for access MMIO regions
Date: Mon, 24 Apr 2017 10:25:27 -0700 [thread overview]
Message-ID: <20170424172527.GA15532@us.ibm.com> (raw)
In-Reply-To: <1493015287.25766.213.camel@kernel.crashing.org>
Benjamin Herrenschmidt [benh@kernel.crashing.org] wrote:
> On Thu, 2017-03-30 at 22:13 -0700, Sukadev Bhattiprolu wrote:
> > +static void *map_mmio_region(char *name, uint64_t start, int len)
> > +{
> > +=A0=A0=A0=A0=A0=A0=A0void *map;
> > +
> > +=A0=A0=A0=A0=A0=A0=A0if (!request_mem_region(start, len, name)) {
> > +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0pr_devel("%s(): request_m=
em_region(0x%llx, %d) failed\n",
> > +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0=A0=A0__func__, start, len);
> > +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0return NULL;
> > +=A0=A0=A0=A0=A0=A0=A0}
> > +
> > +=A0=A0=A0=A0=A0=A0=A0map =3D __ioremap(start, len, pgprot_val(pgprot_c=
ached(__pgprot(0))));
> > +=A0=A0=A0=A0=A0=A0=A0if (!map) {
> > +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0pr_devel("%s(): ioremap(0=
x%llx, %d) failed\n", __func__, start,
> > +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0=A0=A0=A0=A0=A0=A0len);
> > +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0return NULL;
> > +=A0=A0=A0=A0=A0=A0=A0}
> > +
> > +=A0=A0=A0=A0=A0=A0=A0return map;
> > +}
>=20
> That's very wrong. I assume this never worked right ?
Untl recently, only tested on simics and has been working there. On the
hardware, hitting a crash on the first mmio write...
>=20
> MMIO regions must be mapped non-cachable. Only the paste region
which maybe due to this :-) Should I change to pgprot_noncached() for the
MMIO writes?
> requires being mapped cachable. Ask Aneesh for a cleaner way of
> doing it too while at it.
Ok.
>=20
> > +/*
> > + * Unmap the MMIO regions for a window.
> > + */
> > +static void unmap_wc_paste_kaddr(struct vas_window *window)
> > +{
> > +=A0=A0=A0=A0=A0=A0=A0int len;
>=20
> Don't use "wc"... that usually means "write combine".
Ok.
Thanks,
Sukadev
WARNING: multiple messages have this Message-ID (diff)
From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
michael.neuling@au1.ibm.com, stewart@linux.vnet.ibm.com,
apopple@au1.ibm.com, hbabu@us.ibm.com, oohall@gmail.com,
bsingharora@gmail.com, linuxppc-dev@ozlabs.org,
linux-kernel@vger.kernel.org, aneesh.kumar@linux.vnet.ibm.com
Subject: Re: [PATCH v4 05/11] VAS: Define helpers for access MMIO regions
Date: Mon, 24 Apr 2017 10:25:27 -0700 [thread overview]
Message-ID: <20170424172527.GA15532@us.ibm.com> (raw)
In-Reply-To: <1493015287.25766.213.camel@kernel.crashing.org>
Benjamin Herrenschmidt [benh@kernel.crashing.org] wrote:
> On Thu, 2017-03-30 at 22:13 -0700, Sukadev Bhattiprolu wrote:
> > +static void *map_mmio_region(char *name, uint64_t start, int len)
> > +{
> > + void *map;
> > +
> > + if (!request_mem_region(start, len, name)) {
> > + pr_devel("%s(): request_mem_region(0x%llx, %d) failed\n",
> > + __func__, start, len);
> > + return NULL;
> > + }
> > +
> > + map = __ioremap(start, len, pgprot_val(pgprot_cached(__pgprot(0))));
> > + if (!map) {
> > + pr_devel("%s(): ioremap(0x%llx, %d) failed\n", __func__, start,
> > + len);
> > + return NULL;
> > + }
> > +
> > + return map;
> > +}
>
> That's very wrong. I assume this never worked right ?
Untl recently, only tested on simics and has been working there. On the
hardware, hitting a crash on the first mmio write...
>
> MMIO regions must be mapped non-cachable. Only the paste region
which maybe due to this :-) Should I change to pgprot_noncached() for the
MMIO writes?
> requires being mapped cachable. Ask Aneesh for a cleaner way of
> doing it too while at it.
Ok.
>
> > +/*
> > + * Unmap the MMIO regions for a window.
> > + */
> > +static void unmap_wc_paste_kaddr(struct vas_window *window)
> > +{
> > + int len;
>
> Don't use "wc"... that usually means "write combine".
Ok.
Thanks,
Sukadev
next prev parent reply other threads:[~2017-04-24 17:25 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-31 5:13 [PATCH v4 00/11] Enable VAS Sukadev Bhattiprolu
2017-03-31 5:13 ` [PATCH v4 01/11] Add Power9 PVR Sukadev Bhattiprolu
2017-03-31 5:13 ` [PATCH v4 02/11] VAS: Define macros, register fields and structures Sukadev Bhattiprolu
2017-04-04 17:17 ` Sukadev Bhattiprolu
2017-03-31 5:13 ` [PATCH v4 03/11] Move GET_FIELD/SET_FIELD to vas.h Sukadev Bhattiprolu
2017-03-31 5:13 ` [PATCH v4 04/11] VAS: Define vas_init() and vas_exit() Sukadev Bhattiprolu
2017-04-02 20:23 ` kbuild test robot
2017-04-04 17:20 ` Sukadev Bhattiprolu
2017-04-24 6:18 ` Benjamin Herrenschmidt
2017-04-24 6:25 ` Benjamin Herrenschmidt
2017-04-24 20:32 ` Tyrel Datwyler
2017-05-25 5:29 ` Sukadev Bhattiprolu
2017-03-31 5:13 ` [PATCH v4 05/11] VAS: Define helpers for access MMIO regions Sukadev Bhattiprolu
2017-04-24 6:28 ` Benjamin Herrenschmidt
2017-04-24 17:25 ` Sukadev Bhattiprolu [this message]
2017-04-24 17:25 ` Sukadev Bhattiprolu
2017-04-24 23:19 ` Benjamin Herrenschmidt
2017-03-31 5:13 ` [PATCH v4 06/11] VAS: Define helpers to init window context Sukadev Bhattiprolu
2017-03-31 5:13 ` [PATCH v4 07/11] VAS: Define helpers to alloc/free windows Sukadev Bhattiprolu
2017-03-31 5:13 ` [PATCH v4 08/11] VAS: Define vas_rx_win_open() interface Sukadev Bhattiprolu
2017-03-31 5:13 ` [PATCH v4 09/11] VAS: Define vas_win_close() interface Sukadev Bhattiprolu
2017-03-31 5:13 ` [PATCH v4 10/11] VAS: Define vas_tx_win_open() Sukadev Bhattiprolu
2017-03-31 5:13 ` [PATCH v4 11/11] VAS: Define copy/paste interfaces Sukadev Bhattiprolu
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